The two friends were distinct in every thing; dress, manners, hair-style and food habits.

The correct answer is D. different.

The two friends were distinct in every way, which means they were different. They had different styles of dress, different manners, different hairstyles, and different food habits. This suggests that they were not similar in any way.

The other options are incorrect. Option A, similar, is incorrect because the two friends were not similar in any way. Option B, uniform, is incorrect because the two friends were not the same in any way. Option C, opposite, is incorrect because the two friends were not opposites in any way.